This invention relates to check valves and more particularly to a bypass type of valve for fluid filters and the like, which valve is of simplified unitary construction especially suited for assembly and removal from the filter and the like for maintenance purposes or for a change of operating characteristics.
Similar types of valves have been utilized in the past in many different configurations. Once such example is shown in U.S. Pat. No. 3,913,615, designed particularly for fluid filters and the like, and characterized by a simplified assembly of components. In this example, the valve is formed of a minimum of components and is fabricated by the bending of a plurality of struts into a spring housing which then is secured in an annular support by means of a turned-in edge. The necessary spring and poppet are assembled into the housing prior to being secured in the support and the poppet is guided in its movement at its periphery by the four struts forming the housing. While this is an economical design, the entire assembly is not readily removable or replaceable in a filter housing or the like, but rather is designed to be secured in place by staking or a similar operation, and further the spring and valve poppet are permanently retained in the assembly and cannot be interchanged.
Another valve construction which is designed for convenient repair or replacement purposes is shown in U.S. Pat. No. 1,602,372. This valve is designed for use in pumps and the like and consists of a valve base which may be connected in any convenient manner to a pump structure and which includes a rearwardly extending spider having three equally spaced arms which terminate in an end hub and form the spring and poppet housing. In this arrangement replacement of the spring and/or poppet is effected by unthreading the spider from its base whereupon a central bolt can be disengaged from a nut to release the components of the subassembly. While this valve construction provides interchangeability of components, it involves a relatively high number of elements which require manual assembly prior to placement in a filter housing or the like.
A still further variation of prior art valve is shown in U.S. Pat. No. 4,272,368. This valve is also of simplified construction and particularly suited for placement in filter housings and the like, and comprises a structure having a central support member with poppet and spring slidably received thereon and secured by a lock member. This type of valve is reversible in assembly to provide variations in the opening characteristics thereof, and is limited to some extent by the restriction to flow effected by the central support structure. Further, this valve configuration requires a relatively high number of components and is not particularly suited to ready replacement or interchange of components.